Apple limits usefulness of this app? – Periodic Timer Review

The iPhone version of this app is simple and straght forward. It just works. :-) The Apple Watch version of this app is also simple and straight forward. It just works. :-) BUT, if you want to use this app on your Apple Watch while ALSO running the Apple Watch native exercise app, or a 3rd party Apple Watch exercise app...It just does NOT work. :-( I assume this limitation is dictated by Apple and not a coding oversight by the developer. It's a shame as my ideal use scenerio for the Apple Watch is to monitor my workout metrics via the exercise app while at the same time getting periodic reminders to facilitate HIIT workouts. The only solution I have been able to create is to run Periodic Timer on my iPhone and run the exercise app on my Apple Watch. Too bad as I really don't like to bring my iPhone with me on runs.
Review by Mr. Luigi on Periodic Timer.